/* MD5.CPP - RSA Data Security, Inc., MD5 message-digest algorithm
 */

/* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
rights reserved.

License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
or this function.

License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.

RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.

These notices must be retained in any copies of any part of this
documentation and/or software.
 */ 


#include "MD5.h"

/* Constants for MD5Transform routine.
 */

#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* F, G, H and I are basic MD5 functions.
 */
#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))

/* ROTATE_LEFT rotates x left n bits.
 */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation.
 */
#define FF(a, b, c, d, x, s, ac) { \
 (a) += F ((b), (c), (d)) + (x) + (DWORD)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define GG(a, b, c, d, x, s, ac) { \
 (a) += G ((b), (c), (d)) + (x) + (DWORD)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
 (a) += H ((b), (c), (d)) + (x) + (DWORD)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
 (a) += I ((b), (c), (d)) + (x) + (DWORD)(ac); \
 (a) = ROTATE_LEFT ((a), (s)); \
 (a) += (b); \
  }

//////////////////////////////////////////////////////////////////////
// CMD5 construction

CMD5::CMD5()
{
	Reset();
}

CMD5::~CMD5()
{
}

//////////////////////////////////////////////////////////////////////
// CMD5 reset m_nState

void CMD5::Reset()
{
	m_nCount[0] = m_nCount[1] = 0;
	/* Load magic initialization constants. */
	m_nState[0] = 0x67452301;
	m_nState[1] = 0xefcdab89;
	m_nState[2] = 0x98badcfe;
	m_nState[3] = 0x10325476;
}

//////////////////////////////////////////////////////////////////////
// CMD5 add data

void CMD5::Add(LPCVOID pData, DWORD nLength)
{
	unsigned int i, index, partLen;
	BYTE* pInput = (BYTE*)pData;
	
	/* Compute number of bytes mod 64 */
	index = (unsigned int)((m_nCount[0] >> 3) & 0x3F);
	
	/* Update number of bits */
	if ( (m_nCount[0] += ((DWORD)nLength << 3)) < ((DWORD)nLength << 3) )
		m_nCount[1]++;
	m_nCount[1] += ((DWORD)nLength >> 29);
	
	partLen = 64 - index;
	
	/* Transform as many times as possible.	*/
	if ( nLength >= partLen )
	{
		memcpy( &m_nBuffer[index], pInput, partLen );
		Transform( m_nBuffer );
		
		for ( i = partLen ; i + 63 < nLength ; i += 64 )
			Transform( &pInput[i] );
		
		index = 0;
	}
	else
	{
		i = 0;
	}
	
	/* Buffer remaining input */
	memcpy( &m_nBuffer[index], &pInput[i], nLength - i );
}

//////////////////////////////////////////////////////////////////////
// CMD5 transform block

void CMD5::Transform(BYTE* pBlock)
{
	DWORD a = m_nState[0], b = m_nState[1], c = m_nState[2], d = m_nState[3], x[16];
	
	Decode( x, pBlock, 64 );
	
	/* Round 1 */
	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

	/* Round 2 */
	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

	/* Round 3 */
	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

	/* Round 4 */
	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
	
	m_nState[0] += a;
	m_nState[1] += b;
	m_nState[2] += c;
	m_nState[3] += d;
	
	/* Zeroize sensitive information. */
	memset( x, 0,sizeof(x) );
}

//////////////////////////////////////////////////////////////////////
// CMD5 finish hash operation

void CMD5::Finish()
{
	unsigned char bits[8];
	unsigned int index, padLen;
	
	/* Save number of bits */
	Encode( bits, m_nCount, 8 );
	
	/* Pad out to 56 mod 64. */
	index = (unsigned int)((m_nCount[0] >> 3) & 0x3f);
	padLen = (index < 56) ? (56 - index) : (120 - index);
	Add( PADDING, padLen );
	
	/* Append length (before padding) */
	Add( bits, 8 );
}

//////////////////////////////////////////////////////////////////////
// CMD5 encode and decode

void CMD5::Encode(BYTE* pOutput, DWORD* pInput, DWORD nLength)
{
	unsigned int i, j;
	
	for ( i = 0, j = 0 ; j < nLength ; i++, j += 4 )
	{
		pOutput[j+0] = (unsigned char)(pInput[i] & 0xff);
		pOutput[j+1] = (unsigned char)((pInput[i] >> 8) & 0xff);
		pOutput[j+2] = (unsigned char)((pInput[i] >> 16) & 0xff);
		pOutput[j+3] = (unsigned char)((pInput[i] >> 24) & 0xff);
	}
}

void CMD5::Decode(DWORD* pOutput, BYTE* pInput, DWORD nLength)
{
	unsigned int i, j;
	
	for ( i = 0, j = 0 ; j < nLength ; i++, j += 4 )
	{
		pOutput[i] =	((DWORD)pInput[j]) | (((DWORD)pInput[j+1]) << 8) |
						(((DWORD)pInput[j+2]) << 16) | (((DWORD)pInput[j+3]) << 24);
	}
}

//////////////////////////////////////////////////////////////////////
// CMD5 get hash bytes

void CMD5::GetHash(MD5* pHash)
{
	/* Store m_nState in digest */
	Encode( (BYTE*)pHash, m_nState, 16 );
}

//////////////////////////////////////////////////////////////////////
// CMD5 convert hash to string

CString CMD5::HashToString(const MD5* pHash, BOOL bURN)
{
	CString str;
	
	str.Format( bURN ?
		"md5:%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" :
		"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
		pHash->n[0], pHash->n[1], pHash->n[2], pHash->n[3],
		pHash->n[4], pHash->n[5], pHash->n[6], pHash->n[7],
		pHash->n[8], pHash->n[9], pHash->n[10], pHash->n[11],
		pHash->n[12], pHash->n[13], pHash->n[14], pHash->n[15] );
	
	return str;
}

//////////////////////////////////////////////////////////////////////
// CMD5 parse from string

BOOL CMD5::HashFromString(LPCTSTR pszHash, MD5* pMD5)
{
	if ( strlen( pszHash ) < 32 ) return FALSE;
	
	BYTE* pOut = (BYTE*)pMD5;
	
	for ( int nPos = 16 ; nPos ; nPos--, pOut++ )
	{
		if ( *pszHash >= '0' && *pszHash <= '9' )
			*pOut = ( *pszHash - '0' ) << 4;
		else if ( *pszHash >= 'A' && *pszHash <= 'F' )
			*pOut = ( *pszHash - 'A' + 10 ) << 4;
		else if ( *pszHash >= 'a' && *pszHash <= 'f' )
			*pOut = ( *pszHash - 'a' + 10 ) << 4;
		pszHash++;
		if ( *pszHash >= '0' && *pszHash <= '9' )
			*pOut |= ( *pszHash - '0' );
		else if ( *pszHash >= 'A' && *pszHash <= 'F' )
			*pOut |= ( *pszHash - 'A' + 10 );
		else if ( *pszHash >= 'a' && *pszHash <= 'f' )
			*pOut |= ( *pszHash - 'a' + 10 );
		pszHash++;
	}
	
	return TRUE;
}

BOOL CMD5::HashFromURN(LPCTSTR pszHash, MD5* pMD5)
{
	if ( pszHash == NULL ) return FALSE;
	
	int nLen = (int)strlen( pszHash );
	
	if ( nLen >= 8 + 32 && strcmp( pszHash, "urn:md5:" ) == 0 )
	{
		return HashFromString( pszHash + 8, pMD5 );
	}
	else if ( nLen >= 4 + 32 && strcmp( pszHash, "md5:" ) == 0 )
	{
		return HashFromString( pszHash + 4, pMD5 );
	}
	
	return FALSE;
}

void CreateMD5Hash(char szHash[33], BYTE* pData, DWORD dwLen)
{
	CMD5 md5;	
	MD5 md5Hash;
	md5.Add(pData, dwLen);
	md5.Finish();
	md5.GetHash(&md5Hash);

	memset(szHash, 0, 33);
	sprintf(szHash, ("%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"),
		md5Hash.n[0], md5Hash.n[1], md5Hash.n[2], md5Hash.n[3],
		md5Hash.n[4], md5Hash.n[5], md5Hash.n[6], md5Hash.n[7],
		md5Hash.n[8], md5Hash.n[9], md5Hash.n[10], md5Hash.n[11],
		md5Hash.n[12], md5Hash.n[13], md5Hash.n[14], md5Hash.n[15] );
}

